1. Technical Field
The present invention relates to a physical quantity sensor, a physical quantity sensor device, electronic equipment, and a moving body.
2. Related Art
In recent years, a physical quantity sensor for detecting a physical quantity such as acceleration by using, for example, a silicon micro electro mechanical systems (MEMS) technique has been developed.
As the physical quantity sensor, a physical quantity sensor having a movable electrode which has a large plate portion and a small plate portion and is supported on an insulating layer such that the plate portions can oscillate in a seesaw manner, a fixed electrode which is provided on the insulating layer to face the large plate portion, and a fixed electrode which is provided on the insulating layer to face the small plate portion is known (refer to, for example, JP-A-2007-298405).
In the physical quantity sensor described in JP-A-2007-298405, when anodically bonding a structural body (a Si structural body) provided with a movable electrode to a glass substrate, if a glass exposed surface facing the structural body is large, an electrostatic force which is generated increases, and therefore, there is a problem in that sticking of the structural body to the glass substrate occurs.
In order to solve such a problem, an attempt to suppress sticking of a movable body to a substrate by providing an opposite electrode (a dummy electrode) having the same potential as the potential of a movable electrode has been made (refer to, for example, JP-A-2013-160554).
However, in the physical quantity sensor described in JP-A-2013-160554, the occurrence of sticking of the movable electrode can be reduced by the dummy electrode. However, a difference in capacitance (a capacity offset) between each fixed electrode and the movable electrode occurs, and according to the variation thereof, yield is deteriorated beyond an adjustment range of an integrated circuit (IC). Further, there is a problem in that a capacity offset affects the entire sensor (refer to, for example, JP-A-2002-202320).